title: Anti-plasmodial activity of some Zulu medicinal plants and of some triterpenes isolated from them.
abstract: Mimusops caffra E. Mey. ex A.DC and Mimusops obtusifolia Lam (both members of the Sapotaceae family), and Hypoxis colchicifolia Bak (family Hypoxidaceae) are used by traditional healers in Zululand to manage malaria. Anti-plasmodial investigation of the crude extracts and some triterpenes isolated from the plants showed activity against a chloroquine sensitive (CQS) strain of Plasmodium falciparum (D10). Among the crude extracts the leaves of M. caffra exhibited the highest activity, with an IC₅₀ of 2.14 μg/mL. The pentacyclic tritepenoid ursolic acid (1), isolated from the leaves of M. caffra was the most active compound (IC₅₀ 6.8 μg/mL) as compared to taraxerol (2) and sawamilletin (3) isolated from the stem bark of M. obtusifolia (IC₅₀ > 100). Chemical modification of the ursolic acid (1) to 3β-acetylursolic acid (4) greatly enhanced its anti-plasmodial activity. Compound 4 reduced parasitaemia against Plasmodium berghei by 94.01% in in vivo studies in mice. The cytotoxicity of 3β-acetylursolic acid (IC₅₀) to two human cell lines (HEK293 and HepG2) was 366.00 μg/mL and 566.09 μg/mL, respectively. The results validate the use of these plants in folk medicine.
authors.affiliation: Department of Biochemistry & Microbiology, University of Zululand, Private Bag X1001, KwaDlangezwa 3886, South Africa. simelanembc@gmail.com.
authors.forename: Mthokozisi B C
authors.initials: MB
authors.lastname: Simelane
authors.forename: Addmore
authors.initials: A
authors.lastname: Shonhai
authors.forename: Francis O
authors.initials: FO
authors.lastname: Shode
authors.forename: Peter
authors.initials: P
authors.lastname: Smith
authors.forename: Mogie
authors.initials: M
authors.lastname: Singh
authors.forename: Andy R
authors.initials: AR
authors.lastname: Opoku
mesh_terms: D000818:Animals; D000962:Antimalarials / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D002470:Cell Survival / Q000187:drug effects; D004353:Drug Evaluation, Preclinical; D005260:Female; D057809:HEK293 Cells; D056945:Hep G2 Cells; D006801:Humans; D020128:Inhibitory Concentration 50; D008288:Malaria / Q000188:drug therapy*; D008297:Male; D008519:Medicine, Traditional; D051379:Mice; D032130:Mimusops / Q000737:chemistry*; D010936:Plant Extracts / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use; D018515:Plant Leaves / Q000737:chemistry; D010946:Plants, Medicinal / Q000737:chemistry; D010962:Plasmodium berghei / Q000187:drug effects; D010963:Plasmodium falciparum / Q000187:drug effects; D014315:Triterpenes / Q000302:isolation & purification / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000962:Antimalarials; D010936:Plant Extracts; D014315:Triterpenes